ENHANCED GAAS-MESFET CAD MODEL FOR A WIDE-RANGE OF TEMPERATURES

We describe a new and enhanced GaAs MESFET model suitable for implemen tation in computer aided design (CAD) software packages such as, for e xample, SPICE. The model accurately reproduces both above-threshold an d subthreshold characteristics of GaAs MESFET's in a wide temperature range, from 77 K to 350 degrees C. The current-voltage characteristics are described by a single continuous, analytical expression for all r egimes of operation. The physics-based model includes effects such as velocity saturation in the channel, drain induced barrier lowering, fi nite output conductance in saturation, bias dependent series source an d drain resistances, effects of bulk charge, bias dependent average lo w-held mobility, frequency dependent output conductance, backgating an d sidegating, and temperature dependent model parameters, The output r esistance and the transconductance are also accurately reproduced, mak ing the model suitable for analog CAD.